“It’s incredibly emotional and I think in typical This Is Us fashion, we really tried to handle this particular storyline with a lot of sensitivity and respect and grace,” Moore, 34, shared with Us. “It’s a lot to be wading into these waters and I think what’s also been challenging, as an actor, is seeing the way that my character handles the news and the revelation of just how distinctly her life is perhaps going to change. She, again, handles it with such grace and I think I have had to find moments to grieve for her which sounds so bizarre. It makes me like emotional even to talk about.”

“I know what’s in store for her and the fact that she is handling it so stoically and with so much strength, I have to grieve. But I can’t infuse that into character. Having to disassociate myself from it is has been a real challenge,” Moore continued. “We have two more seasons of watching Rebecca on this journey and how it’s going to fundamentally affect the fabric of the family will definitely be something to watch.”

The Emmy nominee also previewed the tension between Randall (Sterling K. Bown) and Kevin (Justin Hartley), as they both have very different methods in taking care of their mother. In a recent flash-forward, it was revealed that the brothers aren’t speaking — and it may have to do with Rebecca.

“I think we’re starting to understand the simmering tensions they have — this sort of longstanding tension that’s kind of been simmering beneath the surface for these brothers for a couple of decades,” Moore explained. “I think this has been a factor in their relationship for longer than they really admit or possibly were even aware of. I think it all comes to a head with them not necessarily being on the same page with how to move forward in terms of caregiving for their mom.”